0.9 Bar is the boiler pressure that a Cuadra's heat exchanger brews great coffee at. The heat exchanger(In these machines) is just a pipe, brazed in place, to run through the boiler. It enters at the side, below the boiler's water level where there is an injector in the fitting to put fresh, cold water from the pump into the first third of the Heat Exchanger (The pipe). The pipe is just a U bend. It runs through the boiler, curves upward and back, breaking the surface of the boiler water and exiting in the "Steam Pocket" section of the boiler. Because the pipe is suspended in a 'higher than boiling' temperature, when there is flow through the heat exchanger the flowing water is heated by the walls of the pipe. The length of the injector matters, because when the brew circuit is flowing, water from both ends of that "Pipe" are flowing toward the group head (Being replenished by water flowing from the injector to a spot in the pipe). I have to draw this on paper, usually, to explain it but try to picture it. If that injector is longer, it puts the new cold water closer to the middle (The bend in a Cuadra's HE). The brewhead recombines the two flows, from top and bottom of the HE, and brews the coffee with that. If the engineer did his calculations right, the recombined streams (After a cooling flush) will be a great temp for brewing. Of course, if the walls of the heat exchanger are significantly hotter or colder than the engineer is imagining(Because of boiler pressure/temperature being well out of range) the brew water from the heat exchanger will be wrong.The brew pressure will be somewhere around 9 Bar. Ten times the boiler pressure. The pressure in the boiler does not affect the pressure in the brew circuit. Think of them as two separate plumbing jobs. In fact, imagine the Heat Exchanger as a separate boiler doing it's own thing. It lives inside the steam boiler to parasitically gather the heat it needs for the brew water, but it is a separate system.

I hope I haven't confused you more. I could have tried to draw you pictures. They wouldn't have helped but you could have gotten a good laugh.

The restrictor controls the flow of the water in the heat exchanger (thermosyphon tubes behind grouphead). The purpose is to lower the overheating of the grouphead. without a restrictor, the 0.9 boiler pressure is a better setpoint to lessen the amount of grouphead overheating to occur. However, it also allows less steaming capacity when steaming a lot of milk.

Vibiemme was one of the first companies to have the restrictor, and many others, like La Nuova Era, followed suit.

I reduced pressure to 0.9-1.0 and there is dramatic difference. I haven't measured temp but based on steam and sputtering (lack thereof) compared to when it ran at 1.0-1.1, I'm not sure if it even needs a flush. There is still plenty of steam for 1-2 drinks.

Are there different types of grouphead thermometers? How much do they cost?

The Ascaso in tank water softener is the recommended replacement to attach to the Cuadra's intake hose. Recharge once per month and replace once per year (email me for instructions if needed). If you have hard water, you may want to recharge more often. When descaling, remove it from the reservoir's intake hose.

The machine does come with one. Prior to first use, the water softener should be inspected to make sure the resin beads are not coming out (from damage in transport). If the resins get to the pump, the pump becomes toast. After inspection, it should be recharged and rinsed prior to first use.

Been awhile since I have been on here. Took me several hours of reading to catch up. First I seen a post made by SStones and wanted to answer that one.

Steve... I am the one with the old house and no ground wires. Had you read further into this thread you would have found that I DID put in a GFI. All that mess from that section by me was because my Cuadra came with a very small fuse. I believe the fuse was for the 220 model for Europe. I eventually went with a larger fuse ... a 12V. This held up for some time but eventually went out too. Jim at 1st-Line had sent some 15A fuses. I put one of these in and have had no further problems with the fuse. When all this was going on Jim also sent me a new relay as someone on here suggested that was my problem and it was carboned up. But it made no difference since it wasn't the culprit.

Ok ... on to my new issues. I have found some info on here regarding some of these issues by reading through all the messages. My Cuadra was not heating up in the morning as it should. I don't have the gage to get the temperature, but it wasn't needed. When I went to do a cooling flush in the morning.... no steam, so I knew it was not right, but not WHY it wasn't working as it should. I then developed a leak... there was water behind the machine. I took the machine apart down the the frame and cannot locate where the water is coming from. Since it didn't heat up when I first turned it on in the morning, I decided to leave it on. BAD idea. Lucky for me my wife was home and awake when the Cuadra decide to engage the heating element and leave it ON. It almost maxed the pressure gage when she heard it and shut it down. I had no time to fool with it so I got my Lelit out and used it until this morning. After reading some posts on here, I took off the side and found the relay was toast. I put in the old one that I kept, and had it working again right away. However it didn't come to temp after 2 hours of warm up. The 2nd shot I pulled a couple hours later was fine.... steam on the cooling flush.

BUT ... I still have a leak I can't find. It's a small leak but who needs a constant wet counter, and this old relay isn't a good one since its case is smoked up too. So I need another relay, and I must still have a problem with the heat up on start up in the mornings. I won't be leaving it on all night.

SO... Jim any ideas on where to look for a leak? or anyone else? Tomorrow I will do a descale, but I am sure this won't take care of any of the current problems. I am glad I read this thread before i called and bothered Jim or Moses, but I would like to get any and all parts I need in one order... the original shipping costs from 1st-Line are HIGH as someone noted.. 10 bucks on a lb of coffee.... other items added on don't seem to raise the shipping much so I would like to do all at once.

If the leak is at one of the boiler fittings, it is usually made obvious by a build-up of calcium at the surface. So, if the leak isn't obvious and is ending up as water on the counter check the cold-water places. I would suspect the little swivel push-connector down on the floor of the machine that divides the water out through the two plastic tubes to the Heat Exchanger inlet and the solenoid valve. If it's not that little connector that's cracked, check the actual hose that goes up to the heat-exchanger inlet. It spends a lot of time up there getting very hot and will eventually crack and disintegrate at the hot end. It may be leaking slightly now if it's about to fall apart. Run the thing with all the panels and and the reservoir carrier off and with the backflush blind in to possibly make the leak more obvious.Good luck.

Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post

Forum Rules:No profanity, illegal acts or personal attacks will be tolerated in these discussion boards.No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum.No SEO style postings will be tolerated. SEO related posts will result in immediate ban from CoffeeGeek.No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum.Who Can Read The Forum? Anyone can read posts in these discussion boards.Who Can Post New Topics? Any registered CoffeeGeek member can post new topics.Who Can Post Replies? Any registered CoffeeGeek member can post replies.Can Photos be posted? Anyone can post photos in their new topics or replies.Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts.Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.